Data-driven characterization of traumatic brain injury severity from clinical, neuroimaging, and blood-based indicators.

The conventional clinical approach to characterizing traumatic brain injuries (TBIs) as mild, moderate, or severe using the Glasgow Coma Scale (GCS) total score has well-known limitations, prompting calls for more sophisticated strategies to characterize TBI. Here, we use item response theory (IRT) to develop a novel method for quantifying TBI severity that incorporates neuroimaging and blood-based biomarkers along with clinical measures. Within the multicenter Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study sample (N = 2545), we show that a set of 23 clinical, head computed tomography (CT), and blood-based biomarker variables familiar to clinicians and researchers index a common latent continuum of TBI severity. We illustrate how IRT can be used to identify the relative value of these features to estimate an individual's position along the TBI severity continuum. Finally, we show that TBI severity scores generated using this novel IRT-based method incrementally predict functional outcome over classic clinical (mild, moderate, severe) or International Mission for Prognosis and Analysis of Clinical Trials in TBI (IMPACT) classification methods. Our findings directly inform ongoing international efforts to refine and deploy new pragmatic, empirically-supported strategies for characterizing TBI, while illustrating a strategy that may be useful to evolve staging systems for other diseases.

Low-Performing Students Confidently Overpredict Their Grade Performance throughout the Semester.

When asked to predict how they will perform on an upcoming exam, students are often poorly calibrated, typically in the direction of overpredicting their performance. Research shows that low-performing students' calibration tends to remain poor across multiple tests over the course of a semester. We tested whether these students remain confident in these erroneously high grade predictions across the semester or whether their confidence wanes, suggesting some degree of metacognitive awareness. In two studies, students made grade predictions prior to taking four in-class exams and then rated their level of confidence in their predictions. Results from both studies showed that miscalibration and confidence remained stable across tests, suggesting that low-performing students continued to believe that they would perform well on upcoming exams despite prior evidence to the contrary.

Reducing Surgical Complications in Spine Patients Through a Medication Management Support Program.

STUDY DESIGN: A hospital-wide medication management program was implemented to ensure that high-risk patients would systematically pause antiplatelet and anticoagulant medications. We analyzed complications before and during the implementation of this program. OBJECTIVE: The goal of the study was to determine if a medication management support program was effective for reducing perioperative complications, including hemorrhage, myocardial infarction, stroke, pulmonary embolism, and deep vein thrombosis. DATA AND METHODS: Using data from the National Surgical Quality Improvement Program database, we examined the presence of 5 complications before and during the implementation of a medication management support program. There were 9732 patients in the clinic population who underwent elective spine surgery between 2011 and 2020 and were included in this analysis. Of those 9732 patients, 7205 had surgery before the introduction of the program, whereas 2527 had surgery at some point after the program was introduced. We conducted a series of Pearson's χ 2 tests to determine the relative frequencies of the complications before and during the program. RESULTS: Results showed that during the implementation of the program, patients were relatively less likely to experience hemorrhage (3.16% vs. 1.11%; P <0.001). The reductions in thrombotic complications were clinically significant: myocardial infarction (0.12% vs. 0.00%), stroke (0.10% vs. 0.04%), pulmonary embolism (0.33% vs. 0.28%), and deep vein thrombosis (0.36% vs. 0.28%). These P values ranged from P =0.08 for myocardial infarction to P =0.67 for pulmonary embolism. CONCLUSIONS: The use of this medication management support program appears effective for reducing the need for blood transfusions and thrombotic complications. While promising, the results should be interpreted with caution as we do not know whether this type of program will be effective for other hospital systems.

Linking Rivermead Post Concussion Symptoms Questionnaire (RPQ) and Sport Concussion Assessment Tool (SCAT) scores with item response theory.

OBJECTIVE: Despite the public health burden of traumatic brain injury (TBI) across broader society, most TBI studies have been isolated to a distinct subpopulation. The TBI research literature is fragmented further because often studies of distinct populations have used different assessment procedures and instruments. Addressing calls to harmonize the literature will require tools to link data collected from different instruments that measure the same construct, such as civilian mild traumatic brain injury (mTBI) and sports concussion symptom inventories. METHOD: We used item response theory (IRT) to link scores from the Rivermead Post Concussion Symptoms Questionnaire (RPQ) and the Sport Concussion Assessment Tool (SCAT) symptom checklist, widely used instruments for assessing civilian and sport-related mTBI symptoms, respectively. The sample included data from n = 397 patients who suffered a sports-related concussion, civilian mTBI, orthopedic injury control, or non-athlete control and completed the SCAT and/or RPQ. RESULTS: The results of several analyses supported sufficient unidimensionality to treat the RPQ + SCAT combined item set as measuring a single construct. Fixed-parameter IRT was used to create a cross-walk table that maps RPQ total scores to SCAT symptom severity scores. Linked and observed scores were highly correlated (r = .92). Standard errors of the IRT scores were slightly higher for civilian mTBI patients and orthopedic controls, particularly for RPQ scores linked from the SCAT. CONCLUSION: By linking the RPQ to the SCAT we facilitated efforts to effectively combine samples and harmonize data relating to mTBI.

How Do Scores on the Functional Status Examination (FSE) Correspond to Scores on the Glasgow Outcome Scale-Extended (GOSE)?

This study was designed to determine how raw scores correspond between two alternative measures of functional recovery from traumatic brain injury (TBI), the Functional Status Examination (FSE) and the Glasgow Outcome Scale-Extended (GOSE). Using data from 357 persons with moderate-severe TBI who participated in a large clinical trial, we performed item response theory analysis to characterize the relationship between functional ability measured by the FSE and GOSE at 6 months post-injury. Results revealed that raw scores for the FSE and GOSE can be linked, and a table is provided to translate scores from one instrument to the other. For example, a FSE score of 7 (on its 0-21 scale, where higher scores reflect more impairment) is equivalent to a GOSE score of 6 (where GOSE is scaled on an 8-point scale, with higher scores reflecting less impairment). These results allow clinicians or researchers who have a score for a person on one instrument to cross-reference it to a score on the other instrument. Importantly, this enables researchers to combine data sets where some persons only completed the GOSE and some only the FSE. In addition, an investigator could save participant time by eliminating one instrument from a battery of tests, yet still retain a score on that instrument for each participant. More broadly, the findings help anchor scores from these two instruments to the broader continuum of injury-related functional limitations.

Improving the Precision of the Glasgow Outcome Scale-Extended Using Item Response Theory: A TRACK-TBI Study.

The Glasgow Outcome Scale-Extended (GOSE) is a functional outcome measure intended to place individuals with traumatic brain injury (TBI) into one of eight broad levels of injury-related disability. This simplicity is not always optimal, particularly when more granular assessment of individuals' injury recovery is desired. The GOSE, however, is customarily assessed using a multi-question interview that contains richer information than is reflected in the GOSE score. Using data from the multi-center Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study (N = 1544), we used item response theory (IRT) to evaluate whether rescoring the GOSE using IRT, which posits that a continuous latent variable (disability) underlies responses, can yield a more precise index of injury-related functional limitations. We fit IRT models to GOSE interview responses collected at three months post-injury. Each participant's level of functional limitation was estimated from the model (GOSE-IRT) and comparisons were made between IRT-based and standard (GOSE-Ordinal) scores. The IRT scoring resulted in 141 possible scores (vs. 7 GOSE-Ordinal scores in this sample of individuals with GOSE scores ranging between 2 and 8). Moreover, GOSE-IRT scores were significantly more strongly associated with measures of TBI-related symptoms, psychological symptoms, and quality of life. Our findings demonstrate that rescoring the GOSE interview using IRT yields more granular, meaningful measurement of injury-related functional limitations, while adding no additional respondent or examiner burden. This technique may have utility for many applications, such as clinical trials aiming to detect small treatment effects, and small-scale studies that need to maximize statistical efficiency.

Functional Status Examination Yields Higher Measurement Precision than the Glasgow Outcome Scale-Extended after Moderate-to-Severe Traumatic Brain Injury.

A limited evidence base supports the Functional Status Examination (FSE) as superior to the more commonly used Glasgow Outcome Scale-Extended (GOSE) for precisely characterizing injury-related functional limitations. The aim of this study was to use modern psychometric tools to test the hypothesis that the FSE is more precise than the GOSE in characterizing individual differences in functional limitations after moderate-to-severe traumatic brain injury (TBI). Secondarily, we sought to confirm that the type of interviewee (patient, significant other) does not affect the test performance of the FSE. Using data from 357 individuals with TBI who participated in the Magnesium Sulfate clinical trial and had six-month outcome data, we performed item response theory (IRT) analyses comparing the FSE and GOSE at six months post-injury. Results showed that the FSE yielded higher measurement precision (IRT test information) than the GOSE across most of the disability severity spectrum. The GOSE yielded more information than the FSE at a very high level of disability, because of the GOSE's assignment of a unique score for individuals who are in a vegetative state. Finally, the FSE showed no evidence of differential item functioning by interviewee, indicating it is appropriate to interview either persons with TBI or significant others and combine data across respondents as is typically done. The findings support the FSE as a viable and oftentimes advantageous substitute for the GOSE in clinical trials and translational studies of TBI.

Suicidal ideation across race in a justice-involved sample: An item response theory approach.

OBJECTIVES: Compared to community samples, rates of suicide are much higher in forensic and correctional settings, yet limited research has focused on the development and improvement of suicide assessment methods used in such contexts. Moreover, despite evidence that suicide assessment varies across Caucasians and African Americans, to our knowledge this important issue has received little attention within higher risk correctional samples. We used Item Response Theory and Differential Item Functioning analyses to address this gap within the literature. METHOD: Specifically, we examined the psychometric properties of the Suicidal Ideation scale of the Personality Assessment Inventory (Morey, 2007) in a large sample of justice-involved individuals. RESULTS: Caucasians report greater suicidal ideation compared to African American participants on average. However, after controlling for mean differences, Caucasians and African Americans differentially endorsed symptoms of suicidal ideation. If the level of suicidal ideation is held constant across racial categories, Caucasians underreported suicidal ideation relative to African Americans. CONCLUSION: Results suggest a nuanced picture of suicidal ideation across racial categories that can be informed by Item Response Theory approaches to scale construction and refinement.

Hallucinations and Delusions Signal Alzheimer's Associated Cognitive Dysfunction More Strongly Compared to Other Neuropsychiatric Symptoms.

OBJECTIVES: Neuropsychiatric symptoms (NPS) are common among individuals with dementia of the Alzheimer's type (DAT). We sought to characterize which NPS more purely relate to cognitive dysfunction in DAT, relative to other NPS. METHOD: Demographic, neurocognitive, neuroimaging, and NPS data were mined from the Alzheimer's Disease Neuroimaging Initiative database (n = 906). Using factor analysis, we analyzed the degree to which individual NPS were associated with DAT-associated cognitive dysfunction. We also employed item response theory to graphically depict the ability of individual NPS to index DAT-associated cognitive dysfunction across a continuum ranging from cognitively normal to mild DAT. RESULTS: Psychotic symptoms (hallucinations and delusions) were more strongly related to the continuum of DAT-associated cognitive dysfunction than other NPS, with the strength of the relationship peaking at high levels of disease severity. Psychotic symptoms also negatively correlated with brain volume and did not relate to the presence of vision problems. Aberrant motor behavior and apathy had relatively smaller associations with DAT-associated cognitive dysfunction, while other NPS showed minimal associations. DISCUSSION: Psychotic symptoms most strongly indexed DAT-associated cognitive dysfunction, whereas other NPS, such as depression and anxiety, were not as precisely related to the DAT-associated cognitive dysfunction.

Functional Status Examination Yields Higher Measurement Precision of Functional Limitations after Traumatic Injury than the Glasgow Outcome Scale-Extended: A Preliminary Study.

The Glasgow Outcome Scale-Extended (GOSE) is one of the most widely used measures of functional limitations after traumatic brain injury (TBI), and is the primary outcome measure used in clinical trials of acute TBI treatment. However, the GOSE appears insensitive to the full spectrum of TBI-related functional limitations, which may limit its potential to capture treatment effects or correlate with other variables that impact outcome. The Functional Status Examination (FSE) was designed to improve on the assessment of injury-related functional limitations using a standardized assessment and wider possible score range. The aim of this pilot study was to employ item response theory (IRT) to test the hypothesis that the FSE yields more precise estimation of functional outcome than the GOSE. Traumatically injured patients (n = 100, 77 TBI, 23 orthopedic injuries) were interviewed at 3 months post-injury using both the GOSE and FSE structured interviews. IRT was used to quantify and compare the tests' information functions, which reflect the degree to which each instrument precisely measures functional limitations across the severity spectrum. Findings were consistent with predictions: the FSE yielded stronger measurement of functional limitations (i.e., higher test information) across a wider range of severity than the GOSE, whether scoring the GOSE from all interview items or using the traditional GOSE overall score. Although the FSE appears to be a promising alternative measure to the GOSE, further research is needed to cross-validate these findings in a larger sample and understand how to best deploy it in clinical and translational research.

Statistical Model of Dynamic Markers of the Alzheimer's Pathological Cascade.

Objectives: Alzheimer's disease (AD) is a progressive disease reflected in markers across assessment modalities, including neuroimaging, cognitive testing, and evaluation of adaptive function. Identifying a single continuum of decline across assessment modalities in a single sample is statistically challenging because of the multivariate nature of the data. To address this challenge, we implemented advanced statistical analyses designed specifically to model complex data across a single continuum. Method: We analyzed data from the Alzheimer's Disease Neuroimaging Initiative (ADNI; N = 1,056), focusing on indicators from the assessments of magnetic resonance imaging (MRI) volume, fluorodeoxyglucose positron emission tomography (FDG-PET) metabolic activity, cognitive performance, and adaptive function. Item response theory was used to identify the continuum of decline. Then, through a process of statistical scaling, indicators across all modalities were linked to that continuum and analyzed. Results: Findings revealed that measures of MRI volume, FDG-PET metabolic activity, and adaptive function added measurement precision beyond that provided by cognitive measures, particularly in the relatively mild range of disease severity. More specifically, MRI volume, and FDG-PET metabolic activity become compromised in the very mild range of severity, followed by cognitive performance and finally adaptive function. Conclusion: Our statistically derived models of the AD pathological cascade are consistent with existing theoretical models.

Contextual consideration of the emergence of alexithymia: A case study highlighting cross-cultural client factors and limited English proficiency.

Alexithymia, characterized by deficits in recognition or expression of emotional experiences, has been demonstrated to be associated with depressive symptoms. In psychotherapy, alexithymia can partly manifest as stunted, disfluent speech when an individual attempts to describe his or her subjective experiences. However, similarly stunted, disfluent speech can be observed in individuals with limited English proficiency who are not diagnosed with a depressive disorder. For individuals who present with both symptoms of depression and limited English proficiency, it can be difficult to determine if disfluent speech is a clinical symptom secondary to depression or simply a byproduct of a language barrier. Determining the underlying cause of speech disfluency is necessary to inform case conceptualization and treatment planning. The following case study describes a Spanish-speaking woman who presented for outpatient psychotherapy to treat major depressive disorder and generalized anxiety disorder. Challenges to the therapy are described; recommendations for English-speaking psychotherapists in similar clinical situations are also provided. (PsycINFO Database Record

Self and informant report across the borderline personality disorder spectrum.

Individuals with borderline personality disorder (BPD) features may be unaware of or unwilling to report their own personality or maladaptive behaviors, which complicates the assessment of BPD. Informants who know the individuals with BPD features may be uniquely suited to aid in the personality assessment of these individuals. The present study analyzed the comparative ability of individuals (targets) and informants to report BPD features across the continuum of BPD severity. The sample consisted of 1387 targets, ages 55 to 65 (56% women), who were recruited for an epidemiological longitudinal study examining the effects of PDs on health and social functioning. Each target nominated an informant who provided information about the target's personality. Results indicated relatively low levels of agreement between perspectives and that informants reported BPD symptoms with more precision and at lower levels of BPD severity than targets. The benefits of including an informant perspective when measuring the BPD continuum are discussed; these benefits may include gains in reliability and improvement in the prediction of outcomes. (PsycINFO Database Record

Alzheimer's Disease Assessment: A Review and Illustrations Focusing on Item Response Theory Techniques.

Alzheimer's disease (AD) affects neurological, cognitive, and behavioral processes. Thus, to accurately assess this disease, researchers and clinicians need to combine and incorporate data across these domains. This presents not only distinct methodological and statistical challenges but also unique opportunities for the development and advancement of psychometric techniques. In this article, we describe relatively recent research using item response theory (IRT) that has been used to make progress in assessing the disease across its various symptomatic and pathological manifestations. We focus on applications of IRT to improve scoring, test development (including cross-validation and adaptation), and linking and calibration. We conclude by describing potential future multidimensional applications of IRT techniques that may improve the precision with which AD is measured.

Item response theory applications in personality disorder research.

This article describes how item response theory (IRT) has begun to address several of the measurement limitations inherent in the personality disorder (PD) literature. In particular, we describe how IRT can be used to improve PD measurement precision, develop PD instruments, and inform PD theory. In closing, we address a key assumption of unidimensional IRT models, and address the need to move beyond these models to include multidimensional models. In this context, we outline what we see as a future direction in PD measurement. (PsycINFO Database Record

Factor structure of the Montreal Cognitive Assessment items in a sample with early Parkinson's disease.

INTRODUCTION: The Montreal Cognitive Assessment (MoCA) is a frequently utilized cognitive screening tool that has attractive clinical attributes when utilized in individuals with Parkinson's disease. However, the construct validity of this instrument has not been well-characterized in Parkinson's samples. The purpose of this study is to explore the underlying factor structure of the MoCA in individuals with early stage Parkinson's disease. METHOD: Item responses from the MoCA in 357 individuals with Parkinson's disease from the Parkinson's Progression Markers Initiative were analyzed first for frequency of errors and polychoric inter item correlations. This correlation matrix was then analyzed with exploratory factor analysis. RESULTS: Omitting items with ceiling effects, three factors emerged which explained the majority of the variance. These factors were reflective of executive dysfunction, memory, and verbal attention. Scores on the MoCA and all of its subscales were significantly different between individuals with Parkinson's disease-no cognitive impairment and those who met criteria for mild cognitive impairment. CONCLUSIONS: In keeping with prior studies in Parkinson's disease, executive dysfunction seems to underpin performance of many items of the MoCA. Implications of this finding both in terms of optimizing the MoCA for use in this population and further steps to validate the constructs behind the MoCA are discussed.

A Statistical Consideration Regarding the Threshold of the Psychopathy Checklist-Revised.

The Psychopathy Checklist-Revised (PCL-R; Hare, 2003 ) is one of the most commonly used measures of psychopathy. Scores range from 0 to 40, and legal and mental health professionals sometimes rely on a cut score or threshold to classify individuals as psychopaths. This practice, among other things, assumes that all items contribute equally to the overall raw score. Results from an item response theory analysis (Bolt, Hare, Vitale, & Newman, 2004 ), however, indicate that PCL-R items differ in the amount of information they can provide about psychopathy. We examined the consequences of these item differences for using a cut score, detailing the consequences for a previously applied cut score of 30 as an example. Results indicated that there were more than 8.5 million different response combinations that equaled 30 and more than 14.2 million that equaled 30 or more. This raw score, like others, corresponded to a broad range of PCL-R-defined psychopathy, indicating that applying cut scores on this measure results in imprecise quantifications of psychopathy. We show that by using the item parameters along with an individual's particular scores on the PCL-R items, it is possible to arrive at a more precise understanding of an individual's level of psychopathy on this instrument.

Methodological issues in the use of individual brain measures to index trait liabilities: The example of noise-probe P3.

Recent research initiatives have called for an increased use of biological concepts and measures in defining and studying mental health problems, but important measurement-related challenges confront efforts in this direction. This article highlights some of these challenges with reference to an intriguing measure of neural reactivity: the probe P3 response, a mid-latency brain potential evoked by an intense, unexpected acoustic-probe stimulus. Using data for a large adult sample (N=418), we report evidence that amplitude of probe P3 response to unwarned noise bursts occurring in a picture-viewing task exhibits robust, independent associations with two distinct trait constructs: weak inhibitory control (or disinhibition; DIS) and threat sensitivity (THT). Additionally, we report a selective association for THT with attentional suppression of probe P3 response during viewing of aversive pictures compared to neutral. These results point to separable elements of variance underlying the probe P3 response, including one element reflecting DIS-related variations in cognitive-elaborative processing, and others reflecting THT-related variations in aversive foreground engagement and abrupt defensive reorientation. Key measurement issues are considered in relation to these specific findings, and methodological and statistical approaches for addressing these issues are discussed in relation to advancement of a quantitatively sound, biologically informed science of psychopathology.

Informant Perceptions of the Cause of Activities of Daily Living Difficulties in Parkinson's Disease.

OBJECTIVE: Individuals with Parkinson's disease (PD) can have difficulties with activities of daily living (ADL) that stem from cognitive, motor, or affective manifestations of the disease. Accurately attributing ADL difficulty specifically to cognitive decline is critical when conducting a neuropsychological evaluation of a person with PD. Informant description of ADL performance is frequently used for this purpose, but there has been little work assessing informants' ability to attribute ADL dysfunction to a specific symptom source in PD. METHOD: Fifty community dwelling individuals with PD completed cognitive, motor, and affective measures. A knowledgeable informant completed an ADL scale that asked about degree and perceived source of difficulty (cognitive, motor, affective) for each task. RESULTS: Informants indicated that motor dysfunction was the most common source of ADL difficulty, but the informants viewed difficulty with certain tasks, such as financial management, as particularly related to cognitive dysfunction. Informant reports of the source of ADL dysfunction (cognitive, motor, affective) were consistent with clinical measures of those specific dysfunctions. ADL dysfunction attributed to cognition specifically (χ(2) = 9.80, p = .01) was higher in those with measurable cognitive impairment. CONCLUSIONS: Informant reports of the sources of ADL dysfunction correlate with clinical measures of these symptoms, suggesting that informants may provide useful clinical information about the cause of ADL dysfunction in persons with PD.

A Dimensional Comparison of a Self-Report and a Structured Interview Measure of Conduct Disorder.

Eligibility for a diagnosis of antisocial personality disorder (ASPD) requires evidence of antecedent conduct disorder (CD). Accurately identifying CD may be influenced by various factors, including assessment methodology. The present study used a two-parameter latent variable model to examine the relative performance of a self-report measure and a structured clinical interview in retrospectively detecting the CD spectrum among adult male offenders (N = 1,159). Self-report and clinical interview tended to converge regarding the rank order of severity indicated by CD symptom criteria. In addition, at relatively low levels of CD severity, self-report provided more information about the CD spectrum than did clinical interview. At relatively higher levels of CD severity, however, clinical interview provided more information about the CD spectrum than did self-report. Latent variable models offer a potential means of combining multiple assessment methods in a way that maximizes information gleaned by capitalizing on the contextual strengths of each approach.